The present invention relates to highway barriers and more particularly, to barriers, sometimes called "jersey walls," which are normally positioned in the middle of a road to serve as lane dividers between opposing streams of traffic. These barriers can also be used for perimeter security around real property, such as an embassy or other location requiring high security measures.
These barriers are generally made of concrete and are designed to withstand lateral force from, for example, a vehicle which is out of control and crashes into the barrier. A problem presented by these barriers is their restriction of vehicle traffic to one direction, such that an emergency vehicle travelling in one direction cannot cross to the other side of the highway to travel in the opposite direction to respond to an emergency situation. Various measures have been taken to minimize this problem. One such measure is to incorporate gaps into a wall of barriers such that the gaps provide an opportunity for an emergency vehicle to make a U-turn for travel in the opposite direction. These gaps, however, present a hazard in that they invite other drivers to make illegal U-turns and inevitably result in accidents.
Thus, there is a need for a movable barrier which prevents drivers from illegally making U-turns but allows police and other emergency vehicles to make U-turns when necessary.
Others have attempted to solve this problem, with varying degrees of success. One drawback of all the prior attempts to solve this problem is that the temporary portion of the barrier does not possess the lateral impact resistance of the adjacent, concrete, substantially fixed barriers. Thus, in a chain of barriers, the "temporary" barrier solutions present weak links in the jersey wall which lack sufficient crash resistance to meet state and federal requirements.
Other problems presented by the solutions to date stem from difficulties arising from inoperability of various sliding or folding mechanisms. For example, systems requiring tracks or pits to be incorporated into the road surface can become jammed or damaged as a result of ice or debris lodging therein. Thus, these designs do not present a solution with long-term viability without an undesired degree of periodic maintenance and housekeeping.
Another problem presented by some attempted solutions is that the "temporary" barrier does not have a profile matching its neighboring concrete barriers. Thus, at the interface between a fixed and "temporary" barrier, edge surfaces can exist which may lead to road hazards.